Electric fluid heater



Nov. 8, 1949 L. P. HYNES 2,487,710

ELECTRIC FLUID HEATER Filed July 16, 1948 2 sheets-sheet 1 L. P. HYNES ELECTRIC FLUID HEATER Nov. 8, 1949 2,487,710

Filed July 1e, 1948 2 sheets-sheet 2 Patented Nov. 8, 1949 UNITED STATES PATENT QFFICE ELECTRIC FLUID HEATER Lee P. Hynes, Haddoneld, N. J.

Application July 16, 1948, Serial No. 38,960

Claims. (Cl. 219-39) The present invention relates to electric heaters for fluids.

A purpose of the invention is to permit more :ready access to the interior of an electric heater for iiuids, for the purpose of inspection and repair.

A further purpose is to provide front and rear walls on an electric heater which are joined to the top, bottom and end walls merely by welds at the outer edges of flanges on the iront and rear walls, which welds connect with the extreme outer edges of the top, bottom and end walls, thus permitting removal of the front and rear walls by cutting off the welds at the edges, and sealing by rewelding.

A further purpose is to provide ribs on the front and rear walls extending outwardly desirably further than the flanges, and to crossconnect and support the ribs by clamps.

A further purpose is to provide end flanges on the top and bottom Walls and to join the end walls to the top and bottom walls by welds at the edges of the flanges, and to joint the end Walls to the front and rear walls by welds at the edges of the end walls and the front and rear walls, thus permitting removal of the end walls by cutting off .the welds, and replacement by rewelding.

A further purpose is to mount the heater elements in pockets extending through openings in the end walls, to support the outer ends of the heater elements on a heater panel located endwise of each end wall, and to surround the heater panel with a main connection box.

A further purpose is to extend a tube from one wall of the main connection box to an auxiliary connection box and to extend bus bars from the auxiliary connection box through the tube and into the main connection box.

'Furtherpurposes appear in the specication and in the claims.

In the drawings I have chosen to illustrate one only of the numerous embodiments in which my invention may appear, choosing the form shown from the standpoints of convenience in illustration, satisfactory operation and clear demonstration of the principles involved.

Figure l is a topY plan View of my improved fluid heater.

Figure 2 is a front elevation of Figure 1.

Figure 3 is a right end elevation of Figure 1, with the cover plate of the main connection box removed.

Figure 4 is a section on the line 4-4 of Figure 2.

Describing in illustration but not in limitation and referring to the drawings:

Fluid heaters of the type in which the heater element is contained within a pocket and extends through an end wall, preferably alternately from alternate ends to form a serpentine path, as shown in my U. S. Patents 1,985,830 and 2,421,562, are extensively used for heating fluids, especially liquids, such as oil, chemicals or the like. rIhese heaters are very efcient and have generally given good service.

From time to time it is necessary to gain access to the interior of the heater, for the purpose of periodic inspection, cleaning, repair or the like, and this has not always been accomplished easily in prior art designs.

Where a removable front wall is provided, bolted in place as in my Patent 2,421,562, there is always the possibility of leakage, and addtional fabrication expense is required to provide the tight fits that are desired on the mating surfaces.

In the construction of the present invention, it is possible to gain access very readily lthrough the front or rear wall by simply cutting olf a single line'of weld around the outer edge and rewelding at such outer edge. In the same way access through an end can be obtained in the new construction by simply cutting off a line of weld around the outer edge at the end Wall. Likewise in the new structure, the electrical connections are greatly improved, permitting operation at higher temperatures without harm to service wiring.

The heater 20 is of generally rectangular form, having a metallic top wall 2i, a metallic bottom Wall 22, metallic end Walls 23 and 24, a metallic iront wall 25 and a metallic rear wall 26.

Hollow flanges 2'1 and 28 extend around the inside of the end wall and are permanently joined as by welding to the ends of the top and bottom walls at 30, extending upwardly and downwardly from such top and bottom walls. At the extreme top and bottom edges the flange 2l is joined to the end wall 23 and the flange 28 is joined to the end wall 24 by a weld line 3|, which is accessible at a distance from the body of the casing for application of the weld and for cutting off the weld for removal of the end wall. The length of the extension of the flange and the end wall from the body should be adequate to permit cutting oil and rewelding several times.

The top and bottom carry inlet and outlet connections 32 and 33, which are suitably welded or otherwise sealed to the top and bottom walls.

the outlet. Attachment of each heater pocket y around the heater opening to the end wall is desirably accomplished by welding.

The front wall 25 and the rear wall 2'6 desirably are of pan-like formation provided with an outer rim or flange 36 extending outwardly all around. The outer edge of the pan is united to the parallel outer edge of the top and bottom wall at 31 by a weld which can readily be cut ofi for removal and rewelded. At the ends of the flange 36 on the front and back wall, the hollow flanges 21 and 28 and the ends 23 and 24 are all carried outwardly away from the body to the same position where all three are united by a weld at 38 extending across the outer edges at a distance far.enough from the body so that the weld can be cut oi and rewelded several times for removal and replacement.

The insides of the front and rear wall carry suitably secured thereto guide plates 40 which are provided, at points corresponding to the positions of the pockets, with channel shaped guides 4| extending in the direction of the pockets so that the pockets can slide for insertion or removal of an end wall.

The outsides of the front and rear walls are provided with ribs 42 suitably secured to the wall as by welding, desirably extending horizontally in spaced relationship, and extending outwardly somewhat farther than the flanges on the pan. The ribs are engaged and supported by clamping bars 43, suitably of angle shape, on either side of the casing which are united at the tcp and bottom by clamp bolts 44.

The end walls 23 and. 24 form the bases of main connection boxes 45 at each end, which conveniently connect through tubular metallic conduits 46, desirably at the back, to auxiliary connection boxes 61. The main connection boxes have front and rear walls 48 and top and bottom walls i9 which are joined at one end to the end walls of the heater and joined at the corners to one another. At the outer ends the main connection boxes carry flanges 5l lwhich make suitably bolted connection with cover plates 52. The joint with the cover plate ordinarily need not be ground, but in the case of explosion-proof equipment a ground joint is desirable.

Inside the main connection box and extending suitably parallel to the ends of the heater are located metallic panels 53, removably fastened to the connection boxes as by bolts. The panels 53 are suitably provided with openings through which insulators 54 are carried to make connection with electric heating elements 56, which extend into the heater pockets and extend outwardly therefrom far enough to provide connection terminals 51 and 58 shown only at the top of Figure 2 on one side. The terminals 58 suitably connect to the appropriate phase bus 60, 6l or 62 which extends desirably vertically over the ends of the heating elements. Thus the panels provide support for the ends of the heating elements, and when in place limit the heater elements from sliding out of the pockets, while at the same time the openings in the panels support the insulators for the connections to the heating elements. In a three phase star connection as shown, a common connection 63 is made between the terminals 51 of all of the heating elements.

Buses 64, 65 and 66 are conveniently carried through the conduit 46, suitably insulated from the conduit and from one another by insulators not shown, and connecting at one end to the phase buses. At the other end the buses suitably -connect to the service, at a point which is far enough removed from the heater to be at suitably low temperature. The auxiliary junction boxV 41, in which the connection to the service is accomplished, conveniently has a cover plate 61 suitably fastened as by bolting and provided with a ground joint in the case of explosion-proof design.

It will be understood' that for moisture-proof operation cover plates on the connection boxes can be provided with gaskets if desired. In operation it will be understood that the equipment will be assembled as described. In case it is necessary to inspectthe interior it will be very convenient to simply take the heater out of service, remove the clamps, and then cut ofi the welds at the outer edges around the pan of one or both front and back walls.

After the inspection, repair, cleaning or the like have been completed the pan can be reinserted and welded back into place by replacing the welds at the outer edges of the flanges on the pan. The clamps can then be restored to position. The difference in lengths of the flanges at the outer ends of the pan makes no diiference in the effectiveness of the clamps as these grip the ribs and not the flanges.

In case it is desired to remove an end Wall, as

for example to replace a heater pocket, it is l simply necessary to cut 01T the outer ends of the welds around the perimeter of the end wall, and then the end wall can be removed, sliding the pockets out through the guides. On replacement of the end wall, it is merely necessary to Weld around the perimeter.

An individual heating element can .be replaced by removing the covers on the main connection box and on the auxiliary connection box, taking out the bus bars, and removing the panel which serves to hold the heater elements in position. It will then be very easy to remove any individual heating element desired, merely by sliding it out longitudinally.

It will be evident that by the invention the ease of disassembly of the equipment and replacement of components is greatly increased, while at the same time the cost of fabrication is reduced. y

In view of my invention and disclosure variations and 'modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of my invention without copying the structure shown, and I, therefore, claim all such insofar as they fall within the reasonable spirit and scope of my claims.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is: v

1. In an electric heater for fluids, top and bottom metallicl walls spaced from one another, metallic end walls having openings and joined to the top and bottom walls at the corners, electric heaters extending through the openings in the end walls and forming a sinuous fluid path, and front and back metallic walls outwardly flanged all around, welded at the ends of the flanges to the top, bottom and end walls, and engaging the heaters to close the front and rear of the sinuous fluid path.

2. In an electric heater for uids, metallic end walls having openings, tubular heater pockets each extending through one opening, joined to the end wall at that opening, and extending part only of the distance to the opposite end wall, the pockets joined to the respective end walls alternating to form a sinuous path, metallic top and bottom walls connected to the end walls at the corners, and outwardly iianged removable front and back walls welded to the end walls and top and bottom walls at the outer ends of the flanges, and meeting the pockets at the front and rear.

3. In an electric heater for fluids, metallic end walls having openings, tubular heater pockets each extending through one opening, joined to the end wall at that opening, and extending part only7 of the distance to the opposite end wall, the pockets joined to the respective end walls alternating to form a sinuous path, metallic top and bottom walls connected tothe end walls at the corners, outwardly flanged removable front and back walls welded to the end walls and top and bottom walls at the outer ends of the anges and meeting the pockets at the front and rear, and spaced ribs secured to the front and rear walls on the outside thereof.

4. In an electric heater for fluids, metallic end walls having openings, tubular heater pockets each extending through one opening, joined to the end wall at that opening, and extending part only of the distance to the opposite end wall, the pockets joined to the respective end walls alternating to form a sinuous path, metallic top and bottom walls connected to the end walls at the corners, outwardly flanged removable front and back walls welded to the end walls and top and bottom walls at the outer ends of the flanges and meeting the pockets at the front and rear, spaced ribs secured to the front and rear walls at the outside thereof, and clamps extending over the outsides of the ribs and cross connected from front to rear.

5. In an electric heater for fluids, metallic end walls having openings, tubular heater pockets each extending through one opening, joined to the end wall at that opening, and extending part only of the distance to the opposite end wall, the pockets joined to the respective end walls alternating to form a sinuous path, metallic top and bottom walls connected to the end walls at the corners, a box having sides extending around the perimeter of each end wall and enclosing the ends of the pockets, joined to such end wall and having an end closure, a mounting panel within the box, electric heater elements in the pockets secured to the mounting panel, and outwardly flanged removable front and back walls welded to the end walls and top and bottom walls at the outer ends of the flanges and meeting the pockets at the front and rear.

6. In an electric heater for fluids, a rectangular casing, heater pockets extending alternately through opposite ends of the casing, main connection boxes on opposite ends of the casing around the ends of the pockets, connection tubes extending from the main connection boxes,

auxiliary connection boxes on the ends of the connection tubes, lbus bars extending from the auxiliary connection boxes through the tubes into the main connection boxes, and heater elements in the pockets, extending into the main connection boxes, and connected therein to the bus bars.

'7. In an electric heater for nuids, a rectangular casing, heater pockets extending alternately through opposite ends of the casing, main connection boxes on opposite ends of the casing around the ends of the pockets, connection tubes extending from the main connection boxes, auxiliary connection boxes on the ends of the connection tubes, bus bars extending from the auxiliary connection boxes through the tubes into the main connection boxes, mounting panels in the main connection boxes, and heater elements in the pockets, extending into the main connection boxes and mounted on the mounting panels, and there connected to the bus bars.

8. In an electric heater for uids, a casing having flat heater pockets extending in from one end and having an open side provided with outwardly extending edges in prolongation of the top, bottom and ends forming a recess, and a removable wall consisting of a rectangular pan having outwardly turned edges parallel to the edges on the recess and provided with inner guides for the pockets, the removable wall fitting into the recess with the edges of the pan aligned side-by-side the edges of the recess and sealed to the edges of the recess around the periphery only.

9. In an electric heater for fluids, a casing having heater pockets and having an open side provided with outwardly turned edges forming a recess, a removable wall consisting of a rectangular pan having outwardly turned edges and having inner guides for the pockets, the removable wall fitting into the recess with the edges of the pan aligned side-by-side to the edges of the recess and sealed to the edges of the recess around the periphery only, the removable side having external ribs extending out farther than the pan edges and clamps around the casing engaging the ribs.

10. In an electric heater, metallic top and bottom walls extending straight outward at the front and rear and upwardly and downwardly flanged at the ends, metallic end walls having openings, extending outwardly all around and welded at the extreme top and bottom to the extreme ends of the flanges on the top and bottom walls, heater pockets extending through the openings on the end walls and welded thereto, and extending alternately from opposite ends, and front and rear metallic walls engaging the heater pockets internally, outwardly flanged all around and welded to the end and top and bottom walls only from the outer edges of the flanges to the forward and rearward edges of the end and top and bottom walls.

LEE P. HYNES.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,847,489 Lonergan Mar. 1, 1932 1,913,923 Freeman June 13, 1933 

